An important factor in the efficiency of a switching power supply is the performance of the diodes used in such circuits. More particularly, the reverse recovery of such diodes can reduce turn-on loss of the transistor switch in such power supplies. For example, a reverse recovery current transient appears as an additional component of current during the turn-on of the switch, with the result that the turn-on loss of the switch is significantly higher that it would otherwise be without such reverse recovery component. Consequently, reducing metal oxide semiconductor field effect transistor (MOSFET) body diode reverse recovery charge (Qrr) and/or reducing reverse recovery time (trr) is important for improving the efficiency of switching power supplies.
Unfortunately, however, if the reverse recovery is too abrupt, then the current and voltage will experience undesirable oscillations. Such oscillations can result in, for example, low efficiency power supply operation, a deleteriously noisy output, e.g., power supply ripple and/or electromagnetic interference, and/or extremely high and possibly damaging voltage spikes.